Gas chromatography is a well established technique for qualitative and quantitative chemical analysis, and gas chromatographs, i.e. G.C.'s, are used worldwide by the industrial, scientific, medical and academic communities. In G.C. analysis, a measured volume of a sample, or specimen, is injected into a substrate filled column and carried therethrough by a continuous flow of an inert or non-reactive carrier gas, e.g. helium, argon, nitrogen and hydrogen. The individual components, or constituents of the sample are separated in the column in accordance with their differing affinities for the substrate employed in the column. The components emerge from the column in characteristic sequence, as elution bands diluted with the carrier gas, and each is monitored by a detector, i.e. a thermal-conductivity detector or flame ionization detector. The detector-output signal is processed electronically, the data output, and graphically recorded. The different components of the sample are generally exhibited as chromatograms and appear in a sequence readily identifiable by their characteristic location on the chromatogram, and each is readily quantified by peak heights, or areas under the curve graphically drawn for a given component, or both.
Samples subjected to G.C. analysis often contain low concentrations of water, or moisture. Quite obviously in most situations it is also desirable, if not necessary, not only to properly identify but to ascertain the amount of water in the sample. Often samples are analyzed solely for the determination of water content. Unfortunately however, it is very difficult and often not possible to reliably determine the amount of water in a given sample by G.C. analysis, especially when the water is present in small and infinitesimal concentrations ranging, e.g., from about 1 to 100 parts per million (ppm), or less, based on the total weight of the sample. Characteristically, the water lags and tails on passage through the system so that the graphical trace representative of the detector-output signal for water can be read only with difficulty, if accurately read at all. Thus, characteristically, the widths of the H.sub.2 O peaks are drastically increased, and the chromatogram heights shortened, and tailed. This is because the water component of a sample tends to wet and adhere to surfaces within the G.C. and auxiliary components of the instrument with which it comes into contact, the moisture lagging and tailing through the instrument. Consequently, accurate analysis for water is impractical, and often virtually impossible: particularly where the water is present in the sample in small and infinitesimal concentrations.